Patents by Inventor Keiji Tomizawa

Keiji Tomizawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20130307889
    Abstract: There is provided an inkjet printing apparatus which can perform stable ejection also in successive printing at high speed even in a case of performing printing in use of a print head provided with an ejection opening surface having hydrophilic properties. The inkjet printing apparatus comprises an inkjet print head wherein the control unit controls the print head such that, in a case where the ejection number of the ink ejected from the print head after removing the ink on the ejection opening surface by the ink removal unit is equal to or more than a threshold, a drive energy amount that is supplied for the preliminary ejection operation is larger than a drive energy amount that is supplied for the preliminary ejection operation in a case where the ejection number is less than the threshold.
    Type: Application
    Filed: May 14, 2013
    Publication date: November 21, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Toshikazu Nagatsuka, Shuichi Murakami, Keiji Tomizawa, Atsushi Omura, Etsuko Sawada, Hiroaki Mihara, Yohei Hamade
  • Publication number: 20130286096
    Abstract: A liquid discharge head includes: a substrate including an element that generates energy to discharge liquid and a liquid supply port; a flow path forming member on the substrate which forms a space therebetween with the substrate and has a discharge port therein, the space constituting a pressure chamber, and a flow path causing the pressure chamber and the liquid supply port to communicate; an interlayer provided between the substrate and the flow path forming member; and a protection layer including metal for protection, wherein the interlayer is disposed so as to avoid a first region corresponding to the element, a second region corresponding to a region of the flow path on a pressure chamber side, and a portion corresponding to a boundary between the first region and the second region, and wherein at least apart of the portion is covered with the protection layer.
    Type: Application
    Filed: April 22, 2013
    Publication date: October 31, 2013
    Applicant: Canon Kabushiki Kaisha
    Inventors: Takuma Kodoi, Keiji Tomizawa, Chiaki Muraoka
  • Publication number: 20130076835
    Abstract: A liquid discharge head includes a plurality of discharge ports configured to discharge liquid, a supply port configured to retain the liquid to be discharged from the plurality of discharge ports, a first pressure chamber including a first energy generation element to discharge a predetermined amount of liquid droplets, a second pressure chamber including a second energy generation element to discharge an amount of liquid droplets greater than the predetermined amount, a first flow path through which the supply port and the first pressure chamber communicate with each other, and a second flow path through which the first pressure chamber and the second pressure chamber communicate with each other.
    Type: Application
    Filed: September 6, 2012
    Publication date: March 28, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masaki Oikawa, Keiji Tomizawa
  • Patent number: 8342631
    Abstract: An objective is to provide an inkjet print apparatus and an inkjet print method capable of a print without concentration unevenness. To achieve the objective, in a multiple-pass print using mask patterns each having low-print-percentage areas and high-print-percentage areas, the print-percentage difference between high-print-percentage areas and low-print-percentage areas is cancelled out in left-edge and right-edge parts of an image to be printed.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: January 1, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masayuki Kyoshima, Masaki Oikawa, Keiji Tomizawa
  • Patent number: 8342645
    Abstract: A printing apparatus prints on a printing medium by scanning a printhead having a plurality of nozzle arrays in a first direction and a second direction opposite to the first direction, and has a structure in which an air flow entering the nozzle array in the scan of the printhead in the first direction becomes larger than an air flow entering the nozzle array in the scan of the printhead in the second direction. The apparatus increases, in scanning in the second direction, discharge speed of ink discharged from at least one nozzle array arranged leeward in the scanning direction of the printhead from a predetermined position on the printhead in the scanning direction to be higher than or equal to the discharge speed of ink discharged from at least one nozzle array arranged windward in the scanning direction of the printhead from the predetermined position.
    Type: Grant
    Filed: April 28, 2010
    Date of Patent: January 1, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Masaki Oikawa, Masayuki Kyoshima
  • Patent number: 8342648
    Abstract: To provide an inkjet head which includes high-density nozzle rows and which does not easily cause an ejection failure due to adhesion of ink mist around ejection orifices when a high-density image of a secondary color is printed with a small number of paths. An inkjet head includes at least two or more types of nozzle rows that eject different amounts of ink. When A is the cross section, with respect to an ink supplying direction, of an ink supply path from each ejection orifice to a supply port and L is the length of the ink supply path, the value of A/L differs between the two or more types of nozzle rows. The nozzle row of which the value of A/L is small is disposed outside an area between the nozzle rows that eject a largest amount of ink and that are arranged next to each other.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: January 1, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Chiaki Muraoka, Yasushi Iijima, Tomotsugu Kuroda, Naoko Tsujiuchi, Mikiya Umeyama, Masaki Oikawa, Yuichiro Akama, Keiji Tomizawa
  • Patent number: 8287091
    Abstract: An inkjet printing apparatus and an inkjet printing method are provided which can minimize air current disturbances that occur between the print head and the print medium and also minimize density unevenness caused by mask patterns. For this purpose, the 2-pass printing is performed such that the high printing ratio region and the low printing ratio region are alternated every pixel in the nozzle-arrayed direction and that adjoining groups of high printing ratio regions are separated from one another by a group of low printing ratio regions that forms a passage wide enough for air currents to pass through.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: October 16, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masayuki Kyoshima, Masaki Oikawa, Keiji Tomizawa
  • Patent number: 8231203
    Abstract: While the print head is reduced in size, the adverse effect of air flows produced by ink droplets as they are ejected from a small number of ejection opening arrays is minimized. A small number of first ejection opening arrays eject one of three primary colors—cyan, magenta and yellow—and a large number of second and third ejection opening arrays eject the remaining two primary colors. A fourth ejection opening array is disposed between the first ejection opening array and the second or third ejection opening array.
    Type: Grant
    Filed: August 6, 2009
    Date of Patent: July 31, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuichiro Akama, Keiji Tomizawa, Toru Yamane, Masaki Oikawa, Genji Inada, Mikiya Umeyama, Chiaki Muraoka, Tomotsugu Kuroda
  • Patent number: 8210655
    Abstract: The present invention provides a liquid ejection head for which the peeling of an orifice plate from a substrate seldom occurs, even in a structure such that the walls that define each energy application chamber are narrowed toward an ejection port. The walls that define a first pressure chamber are inclined inward within the first pressure chamber, so that the first pressure chamber is narrowed, toward an ejection port, along a direction perpendicular to the heater formation face on which heaters are arranged. Further, the walls that define each ink flow path are inclined in the ink ejection direction. Furthermore, the angle at which the walls that define the ink flow path are inclined relative to the ink ejection direction is smaller than the angle at which the walls that define the first pressure chamber are inclined inward, within the first pressure chamber.
    Type: Grant
    Filed: February 2, 2009
    Date of Patent: July 3, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Chiaki Muraoka, Yukuo Yamaguchi, Mikiya Umeyama, Toru Yamane, Masaki Oikawa, Yuichiro Akama, Keiji Tomizawa, Tomotsugu Kuroda
  • Patent number: 8177329
    Abstract: An object of the present invention is to provide an ink jet print head having plural types of nozzles arranged on the same substrate and through which ink droplets of different sizes are ejected, the ink jet print head exhibiting acceptable ejection performance regardless of the type of the nozzle. Thus, according to the present invention, each of the plural types of nozzles includes a bubbling chamber having an ejection energy generating element allowing an ink droplet to be ejected to a position located opposite an ejection port and an ejection port portion allowing the ejection port and the bubbling chamber to communicate with each other. Ratio of opening area of the ejection port portion at a position where the ejection port portion and the bubbling chamber communicate with each other, to the opening area of the ejection port is higher for the nozzle with a smaller ejection amount.
    Type: Grant
    Filed: April 1, 2010
    Date of Patent: May 15, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mitsuhiro Matsumoto, Mineo Kaneko, Ken Tsuchii, Toru Yamane, Masaki Oikawa, Keiji Tomizawa, Shuichi Ide, Kansui Takino, Naozumi Nabeshima
  • Patent number: 8162446
    Abstract: The present invention provides a print head that allows the characteristics of ejected ink to be adjusted for each ejection port in spite of a variation in the distance from an ink supply port to the heating element. In the print head according to the present invention, the area of the heating element decreases with increasing distance from the ink supply port and increases with decreasing distance from the ink supply port. The heating element is shaped like a rectangle that is longer in a direction orthogonal to a direction in which the plurality of ejection ports are arranged than in the direction in which the plurality of ejection ports are arranged. The aspect ratio of the heating element depends on the length of an ink channel through which ink is introduced into the bubbling chamber.
    Type: Grant
    Filed: March 24, 2008
    Date of Patent: April 24, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Mineo Kaneko, Ken Tsuchii, Toru Yamane, Masaki Oikawa, Mitsuhiro Matsumoto, Naozumi Nabeshima, Shuichi Ide, Kansui Takino
  • Patent number: 8132895
    Abstract: This invention is directed to a head substrate capable of high-quality printing even when the environmental temperature, print duty, and printhead itself change, a printhead, a head cartridge, and a printing apparatus using the printhead. The head substrate includes a plurality of heaters, a constant electric current source which generates a constant electric current used to drive the heaters, and a reference current generation circuit which generates a reference current for generating the constant electric current. The head substrate also includes a MOSFET which drives the heaters by the constant electric current obtained by driving the constant electric current source in accordance with the reference current, and a switch which determines the time for which the reference current is generated. The open-close time of the switch can be externally controlled.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: March 13, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Masaki Oikawa
  • Patent number: 8100505
    Abstract: A liquid ejecting head includes a substrate, a nozzle forming member for forming on a principal surface of the substrate a nozzle comprising a flow passage of liquid and an orifice for ejecting the liquid, and a dummy pattern. The dummy pattern has substantially the same dimension as at least a part of the nozzle and is formed so that a cross-section of the dummy pattern is exposed at an end surface of the nozzle forming member.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: January 24, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tomotsugu Kuroda, Toru Yamane, Mikiya Umeyama, Masaki Oikawa, Yuichiro Akama, Chiaki Muraoka, Keiji Tomizawa
  • Patent number: 8087759
    Abstract: The impact accuracy of ejected droplets, the quality of printed images, and print speed can be improved in a print head having an ink channel for which the width thereof in a direction orthogonal to an ink supply direction in which ink is supplied from an ink supply port to a pressure chamber is smaller than that of a pressure chamber. In the print head, the center of a heater along the ink supply direction is offset from the center of the pressure chamber along the ink supply direction, toward the side of the pressure chamber far from the ink supply port in the ink supply direction.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: January 3, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Oikawa, Keiji Tomizawa, Mikiya Umeyama, Toru Yamane, Yuichiro Akama, Chiaki Muraoka, Tomotsugu Kuroda, Shingo Nagata, Satoshi Kudo
  • Patent number: 8083322
    Abstract: An ink-jet recording head includes a discharge-port portion including a first discharge-port portion continuing from a discharge port, and a second discharge-port portion communicating the first discharge-port portion with a bubble generation chamber. The second discharge-port portion has an end surface that includes a border portion bordering the first discharge-port portion and is parallel to a main surface of an element substrate. The cross-sectional area of the second discharge-port portion, anywhere from an opening surface facing the bubble generation chamber to an end surface facing the first discharge-port portion, that is parallel to the main surface of the element substrate, is larger than the area of the border portion. The cross-section of the opening surface of the second discharge-port portion has a length in a direction perpendicular to an arrangement direction of the discharge ports that is greater than its length in a direction parallel to the arrangement direction.
    Type: Grant
    Filed: October 27, 2009
    Date of Patent: December 27, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Shuichi Murakami
  • Patent number: 8033651
    Abstract: A reliable print head with improved reliability is less likely to be damaged by possible cavitation in ink inside a bubbling chamber. A plurality of ink supply paths through which the ink is supplied to the bubbling chamber are connected to the bubbling chamber. Communication positions where the plurality of ink supply paths communicate with the energy acting chamber are formed such that distances from a heater formation surface of the communication positions are different from each other along a direction orthogonal to the heater formation surface.
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: October 11, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Ken Tsuchii, Shuichi Ide
  • Patent number: 7984976
    Abstract: A liquid recording head includes an element substrate on which ejection energy generating elements for generating energy for ejecting droplets of liquid are provided in a staggered arrangement, ejection outlets provided opposed to the ejection energy generating elements, ejection energy generation chambers enclosing the ejection energy generating elements, and a flow path constituting member constituting first and second nozzles for supplying the liquid into the ejection energy generation chambers. The second nozzles have flow path lengths shorter than those of the first nozzles, the first and second nozzles are arranged alternately, and an average height of the paths of the first nozzles is greater than that of the paths of the second nozzles.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: July 26, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiji Tomizawa, Ken Tsuchii
  • Patent number: 7980663
    Abstract: A print head can improve an ink refill speed to reduce the time from the end of one ejection of ink droplets until the beginning of a next ejection of ink droplets and maintain the high quality of images obtained by printing. An ink jet print head has an ejection port portion including a first ejection port portion communicating with atmosphere, and a second ejection port portion having a cross-section which extends in a direction orthogonal to an ejecting direction and which is larger than that of the first ejection port portion. The second ejection port portion is formed between a bubbling chamber and the first ejection port portion. In the ink jet print head, an ejection port portion first axis is located away from an ejection port portion second axis.
    Type: Grant
    Filed: August 21, 2009
    Date of Patent: July 19, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mitsuhiro Matsumoto, Keiji Tomizawa, Shuichi Murakami
  • Patent number: 7963633
    Abstract: An ink jet recording head and an ink jet recording apparatus are provided to prevent occurrence of a white line or recording unevenness due to a head tilt, and realize a high image quality recording. For this purpose, in a recording head provided with nozzles ejecting three types of droplets, a large droplet, medium droplet and small droplet, nozzles are configured such that no nozzles are arranged on the same line at the centers thereof in the main scanning direction.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: June 21, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Oikawa, Mineo Kaneko, Ken Tsuchii, Toru Yamane, Keiji Tomizawa, Mitsuhiro Matsumoto, Shuichi Ide, Kansui Takino, Naozumi Nabeshima
  • Patent number: 7963635
    Abstract: The landing precision of ink drops is improved to improve the image quality and increase the printing speed. An inkjet print head ejects ink supplied from an ink supply port from a plurality of ejection ports respectively connecting to ink paths having different flow resistances by using energy generated by a plurality of electrothermal transducer elements respectively corresponding to the plurality of the ejection ports, wherein each of the plurality of the ejection ports connected to the ink paths having a low ink flow resistance is arranged so that the center of each of the plurality of the ejection ports is positioned farther away from the ink supply port to the center of the corresponding electrothermal transducer element than each of the plurality of the ejection ports connected to the ink paths having a high ink flow resistance.
    Type: Grant
    Filed: December 4, 2008
    Date of Patent: June 21, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Oikawa, Keiji Tomizawa, Mikiya Umeyama, Toru Yamane, Chiaki Muraoka, Yuichiro Akama, Tomotsugu Kuroda